Both Sam and Ferne have been given series by ITVBe focusing on the apparently lucrative 'mummy market'.
Ferne's reality show First Time Mum debuted as a one-off last year but is now set to return for a second series.
A three-part follow up series has reportedly been commissioned, following Ferne and her new life with baby Sunday.
Meanwhile, Billie Faiers joins sister Sam Faiers for a third series of The Mummy Diaries on ITVBe, which continues tonight (Wednesday, April 4) at 9PM.
Sources have claimed that the rival shows have prompted a 'bitter feud' between the former TOWIE stars.
An insider alleged to heat magazine: "Sam's team are furious as they've heard Ferne got £250,000 for her reality show in December, whereas Sam only got a tenth of that for her first show.
"They feel like Ferne is trying to steal Sam's thunder and muscle in on her territory. It was nothing malicious on Ferne's part, as her management always wanted her to go down the reality TV route, as she's so popular."
Speaking to the Daily Mirror newspaper, Sam admitted that she and Ferne "haven't seen eye to eye" but insisted there wasn't a "major" feud between them.
Sam revealed: "Over quite a long period of time we haven't seen eye to eye on a number of things.
"We've drifted apart from each other. We've grown up and grown apart but there's no major feud."